Piston ring



July 21, 1925.

1,546,825 G. T. CLARK PISTON RING Filed March 2, 1920 2 Sheets-Sheet 2 a f g 5g Inventor- Zflz'tnass: Q I w I Fay. 7 6y Patented July 21, 192 5.

Bin-Em GEORGE T. -CLARK, OF OIJD ORCHARD; MAINE;

PISTON RINGI Application =fi1ed-March 2, 1920., SeriaLNo, esaei'sa To. all whom itmey concern;-

Beit. known thatI, GIQORGE T. OL ARK,.,EL citizenwof. the United. States, resid1ng at Old Orchard, in .the county lo-f York, State 5 of,Maine, ha,ve inventedaicertain new and useful Improvement in Piston Rings, of Which the following is aspecification, ref erence beingv had therein totthe accompany-v ing-drawings...

1 The inventionv relates .to, packing rings.

. for pistons, more especially such, as are used in connection. with ,the pistons} of internal v combustion engines although packing rings embodying therfeatures of the invention are A not necessarily restricted to i use. in that connection. V

The inventionv isrmore particularly an improvement in. .packingrings of the class which arei expansible. inI width vto fit. the

grooves provided fortheir[reception-in the peripheriesof pistons... It provide/sea packing, ring having: advantages over prior ringsof such class.

Therinvention consistsrin a packing ring composed of divided.'ring;shaped members.

or elements which are .combined with each other in, novel mannen whereby relative 1'07 tary shift of the same operatesto.,vary ,the

Width of, the assembled (unit to fit, .the-width of the piston: groove which it occupiesgin; use. In the, prefer-red formoof embodiment, the construction: such as to render. the component elements orimembers of the packing ring-.self-adjusting;

The d zawings i-llustrate-- the invention. in. the best forms of embodiment whichI have thus far devised. In thedrawings r Fig, .1 shows a,.por-tion .of an ,engine-cylinder, and .a, piston, both,,in. vertical. sec-.-

packing rings. of one of, the formsaafores said. a

Fig. 2 is an edge view of one of the pack ing rings of.,Fig. 1 detached and inits expanded state.

Fig. 3 is a plan view thereof.

Fig.4 is a: plantview of the inner element of the said packing ring, shown separately.

Fig. 5 is a View ofthe saidinnerring element in vertical. section on line ,5 .5 of Fig. 4.

Fig. 6 is a plan of the outer ring-element, and Fig. 7 is a view thereof in vertical section on line 77 of Fig. 6.

tion,.the said piston having applied thereto.

Fig. 8,is asectionalview-filhistratingans other-form of embodiment of the. features. of the invention. 7

In, Fig. 1, the portionpof an enginecylin der thatis shown therein .ismarkedglnthe piston. being marked 2; and-,3, 3,,3, are theeo groovesthat are formed. in the pistonfor the reception of packing rings,,three,such;, rings beingshownin place; V

Considered as a unit,v a packing ring ems, bodying: the, invention, is. composed: of- 3. .65 pluralityv of component ring-shaped :mem; bers or elements nested together one =i115id8:. another in. concentric or substantially. concentric relationship. The forin of embodi; ment illustrated by Figs. 1, to. 7 comprisestwo such members or elements, namelvanfl outermember or element a. and an inner onewb, fitting together. The formillus;v trated by Fig. 8 comprises threeof the said members or elements namely tWo outer ones, 7 5

a" a" and an inner one 6? ,with said outer;

ones fitted, to, the upper and lower-portions respectively, ofthe periphery of the. inner] one.

To ensure theelastic fit against the innerSO surface ,of the enginecylinder that is ,rrer quired in; thecase of a packing ring, each, of the ring-shaped members or elements is dividedor open transversely, ,SQxtllZttfitlQh... membelnor element is what Iterma dividr. ed ring, and I each thereof is, elastic, and. tends its elasticity to assume asradially expandedcondition in whichv itsendspare separated from each; other somewhat. The. ends .of anyouter-member. or element are, stepped'tooverlap with eachother and. form V a stepped joint suchv as is ,usual andwellknown. in ,thecase of packing rings, asin the. case of the ends w, a, of the member a in Figs. 2,3 and 6.. The ends'of ,an inner member or element. maybeplaim: as in the. case-of. ends 1), b, of member I), in Figs.

3 and 4. In practice, however, the-endsof: each ofthe rings composingv a packing ring unit, embodying. the invention may. be, ofi, 1 step formation if deemed advisable.

I1ieach of the. illustrated. embodiments of thQdDVgIltlOllyjllfl alterationz of the Width. of the assembled unit through. relative rotary shift of its component members or ele- 10 ments is provided for by constructing the latter so as to have screw-threaded connection with each other. Thus, referring more particularly to Figs. 1 to 7, the outer ringshaped member or element, a, is internally threaded and the inner one, 6, externally threaded, and the two screw-threaded portions, a 5 are adapted for mutual engage ment. In Fig. 8, the outer and inner members or elements are correspondingly screwthreaded and engaged with one another. In virtue of this mode of engagement, relative turning movement of the outer ring-shaped member or members and inner member will effect relative axial shift or displacementof the component members or elements of a pended upon in some cases, but I have found that automatic or self-adjustment may be secured.

Preferably, I ensure automatic or seif-adjustment of the packing ring in the proper direction to take up lost motion within the piston groove by forming, as shown in the drawings, the screw-threaded interengaging portions of its ring-shaped members or ele ments on a taper. Thus, in the case of the first embodiment aforesaid of the invention, I form the inwardly facing screw-threaded portion cf, Fig. 7 of the external member or element a tapered in one direction, and form the screw-threaded outer circumference b of the inner member or element Z) reversely tapered to match or fit said outer member or element. The result of this construction is that when the two ring-shaped members or elements, properly related, occupy the piston groove, the tendency of the inner member or element Z) to expand, coupled with the continual slight working of the two members or elements a, 6, upon each other, will operate automatically to increase the width of the packing ring because of the tendency of the inner member or element 1) to work axially out of. the outer member or element a in the direction of the outward flare of the latter.

The component divided ring-members or elements are, in being placed together preparatory to insertion into a groove in a piston, so combined and so adjusted relative to each other that they break joint with each other, i. e., the opening or interruption between the ends of the inner member occupies a position offset angularly with reference to that between the ends of'the outer member. Thereby, as will appear from Fig. 2, the inner member or element covers the interruption or opening in the outer member or element, and vice versa. IVith the two members or elements related properly to fit substantially the groove within which they are applied, only a limited extent of turning movement can occur, less than enough to carry the openings of the two members or elements around into register with .each other. in Fig. 8, the inner member or element 6, has a double taper, namely in both directions from the middle of its width toward its edges, while the outer members or elements a a, are conversely tapered to fit the respective portions of member or element to which they are applied. Preferably, the screw-threads upon the upper and lower portions of the inner member are respectively right-hand and left-hand, in order that turning movement in a given direction may cause the two outer members to move simultaneously either toward or from each other, as the case may be.

I claim as my invention- 1. A packing ring comprising component ring-members, one radially inside the other, with the external periphery of the inside ring engaged with the internal surface of the outside ring by means whereby relative rotary adjustment of one ring-member with respect to the other operates to vary the width of the packing ring'axially.

2. A packing ring comprising ring-members in mutual screw-threaded engagement whereby relative rotary adjustment of the said ring-members is caused to vary the width of the packing ring axially.

3. A packing ring comprising component ring-members provided with screw-threaded interengaging portions formed on a taper whereby said packing ring is rendered selfadjusting in respect of its axial width during its operation upon a piston.

A packing ring comprising divided ring-members in mutual screw-threaded engagement providing for relative rotary adjustment of said members into positions in which they break joint with each other, and for varying the width of the packing ring axially,

In testimony whereof I afiix my signature in presence of two witnesses.

GEO. T. CLARK. IVitnesses CHAS. F. RANDALL, ROBERT K. RANDALL.

In the case of the construction shown. 

